170,560 research outputs found
A Monte Carlo program to design a transition radiation detector
No full textAMonteCarloprogram to designatransition radiator detector is described. The program provides the possibility to calculate the X-ray yield from radiators of different materials and structures, and analyzes the transitionradiation energy release in various gaseous detectors
A fast transition radiation detector for high-energy particles selection and triggering
No full textIn this paper we exploit the capability of a transition radiation detector to select different mass particles in a high-energy unseparated beam and to provide a prompt identification signal that can be used as a first level trigger for the physical event acquisition. Various studies on prototypes and measurements on electron/hadron test beams at CERN and BNL are presented: on the basis of the results obtained we show that we can promptly separate electrons from pions starting from 1 GeV/c momentum and we discuss about the possibility to distinguish as well pions from protons in the hundred GeV/c range of momentum at the level of a few percent of particle mis-identification. (C) 2000 Elsevier Science B.V. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A fast transition radiation detector for first-level triggering
No full textWe have designed and tested a transition radiation detector able to select different mass particles in a high-energy unseparated beam and to provide a prompt identification signal that can be used as a first-level trigger for the physical event acquisition. A measurement on electron/hadron test beam at CERN is presented: on the basis of the results obtained we show that we can promptly separate electrons from pions starting from 1 GeV/c momentum and we discuss about the possibility to distinguish as well pions from protons in the hundred GeV/c range of momentum at the level of a few percent of particle mis-identification. (C) 2001 Elsevier Science B.V. All rights reserved
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
A high-precision drift straw tube counter for particle tracking for accelerator and space experiments
No full textWe have designed and tested a straw tube detector prototype to investigate the possibility to operate a full-size device in sealed mode with extremely reduced gas leaks in accelerator experiments and astroparticle physics researches in outer space. In order to acheive a high spatial resolution we tested a "cool"-gas-based mixture, namely, argon-carbon dioxide at atmospheric pressure. In our tests, running the straw tube counter in drift mode with properly designed front-end electronics, we obtained a single-tube spatial resolution of the order of 30 mu m. (C) 1998 Elsevier Science B.V. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A DIRECT MEASUREMENT OF THE ENERGY-SPECTRUM OF COSMIC-RAY MUONS IN THE MONT-BLANC UNDERGROUND LABORATORY
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